iii. An Induced Change in Consumption:
A multiplier increase in income may create expectation of further rises and so cause people to spend more out
of a given income and will set off further multiplier effects
iv. Induced Changes in Investment:
If we consider induced investment also, income change will be greater. A multiplier effect which increases con-
sumption and brightens investment prospects will induce increases in investment.
This, in its in turn, will lead to further multiplier process. That is, if investment like consumption depends on
income or its change, the multiplier effect will be stronger. From this proposition Sir John Hicks developed the
concept of super-multiplier.
v. An Output Lag:
If there is an output lag, i.e., if producers do not immediately increase output to meet an increase in total
demand and allow their stocks of goods to run down, the multiplier effect will be partly lost. The same thing
happens if there is consumption lag, i.e., if households who receive an increase in their income take time to
adjust their consumption habits.
vi. Business Saving:
Finally, if companies do not distribute the major portion of their profits to shareholders in the form of dividends
and increase their reserves of undistributed profits the aggregate MPS will rise and the size of the multiplier is
reduced.
Illustration
Investment multiplier (or Keynesian multiplier) is the idea that an initial investment of ₹100, will cause the total
income in the entire economy to increase by more than ₹100. Here’s an illustration of how this happens (at least
in theory).
First, assume that when people receive an increase in income of ₹100, they will spend some of the additional
income, and save the rest. For our example, let’s say people spend ₹90 out of the ₹100 of additional income.
The following is the series of events that will happen in this model.
The initial investment of ₹100 is paid to someone (let’s call her Alice), so total income in the economy
increases by ₹100.
Alice is now ₹100 richer. Based on our assumption, she will spend 90% of it, which is ₹90. Again, national
income increases by another ₹90. This ₹90 is paid to someone (let’s call him Bob), who receives it as additional
income.
Bob is now ₹90 richer and spends 90% of his additional income (₹81). He pays this to Charles who…
This goes on forever and ever.
If we add up the total increase in national income, we get
National Income=₹100+₹90+₹81+₹72.9+...
This is what mathematicians call a geometric series and there are formulas for finding the answer. This will add
up to ₹1000. So, in this case, our initial investment of ₹100 is multiplied 10 times, causing the national income
to increase by ₹100×10=₹1000.
MPC was assumed to be 0.9. Therefore, using formula also we get 10 times:
?=
1
1 −/2%
=
1
1 − 0.9
=
1
0.1
= 10 6EIAO